From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 25CAD3BE642; Wed, 30 Sep 2026 18:20:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792411; cv=none; b=oAP5+sG7OxRW6MI+M/RolqqiFwEOLUMqjA4u3xFxlw89Dkl+al3JOz9aR3d9zMXfDhTx0U7mEp4Q07orpl1hb09y7aIytk9RQhXkAr8e69tYXKoaS6V6C9lhvwACPi35cztpFcRuRgeIyteTOn5oq1a3HyPxPlet+aI2WriByoA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792411; c=relaxed/simple; bh=QRLKYZdmaUh2IU2cNHOoavrQ4BrpjfklRRwRhKhX7UQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VPvXbg8czPllII/pZzmVipFgQdu/Fi1Ap6kALsEXtmVhqlaqxPlydXN/7HxQxQdHqhRWncJ9/zwgTibAAmJa1H7MVzMgZ5qhfOGnWpXtOK52xihZxnQHsdJSj8PEuh0UgUxVOnVB5GWzKHMvnDj3r17ZWf6z0X7eRkUBvBzYLBA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XJ3lX+YS; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="XJ3lX+YS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 092791F000FF; Wed, 30 Sep 2026 18:20:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790792409; bh=dEzif+u9P+B6Ucj2mm05h6N/1MHJrZyanOJWMYs/H1M=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=XJ3lX+YS1lVS1xt2byR2o2VjInD/KWgNsg4FvTX6Ianrnq0epzdiu9L/+q1QK2QKN 5YekJB89dFh5CgwdbGQiNSDeRVr5NN6TDYPfvNHGj1qc3lgCb2WqI3rYjDJ0Ld5jbN CjGqjBlc60efot0x5+hKH/c79EvtduGhhsttYX9I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, William Bezenah , Vineeth Vijayan , Peter Oberparleiter , Heiko Carstens , Sasha Levin Subject: [PATCH 5.15 608/752] s390/cio: Fix cio_update_schib() to not cache invalid schib Date: Wed, 30 Sep 2026 17:27:58 +0200 Message-ID: <20260930152411.439272673@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152358.131179731@linuxfoundation.org> References: <20260930152358.131179731@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vineeth Vijayan [ Upstream commit 29d9e5835d89223aa913dcf7b942cc1c148bdd25 ] When pmcw.dnv is 0, the contents of all SCHIB fields are unpredictable. Zero sch->schib in that case to prevent subsequent code from making decisions based on unpredictable data. Reported-by: William Bezenah Signed-off-by: Vineeth Vijayan Reviewed-by: Peter Oberparleiter Fixes: 8c58a229688c ("s390/cio: Do not unregister the subchannel based on DNV") Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- drivers/s390/cio/cio.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c index 54bfa9fe3031b..dc798baf4d49d 100644 --- a/drivers/s390/cio/cio.c +++ b/drivers/s390/cio/cio.c @@ -453,7 +453,8 @@ EXPORT_SYMBOL_GPL(cio_commit_config); /** * cio_update_schib - Perform stsch and update schib if subchannel is valid. * @sch: subchannel on which to perform stsch - * Return zero on success, -ENODEV otherwise. + * Return zero on success, -ENODEV if the subchannel is not operational, + * -EACCES if the subchannel has no valid device. */ int cio_update_schib(struct subchannel *sch) { @@ -462,10 +463,12 @@ int cio_update_schib(struct subchannel *sch) if (stsch(sch->schid, &schib)) return -ENODEV; - memcpy(&sch->schib, &schib, sizeof(schib)); - - if (!css_sch_is_valid(&schib)) + if (!css_sch_is_valid(&schib)) { + memset(&sch->schib, 0, sizeof(sch->schib)); return -EACCES; + } + + memcpy(&sch->schib, &schib, sizeof(schib)); return 0; } -- 2.53.0